METACRAN mirrors CRAN packages at GitHub. Each CRAN package lives in its own github repository, .g. package Rcpp is at All versions of all packages are included, and each version is a separate git commit, tagged with the version number. We tried to keep the original dates and authors/maintainers as well.

The main goal of CRAN @ GitHub is the easy access to the source code or CRAN packages. In particular, you can

CRAN versions{package}

Shows the version number of the package on CRAN, or “not published” if the package is not published on CRAN.

CRAN release dates{package}{package}{package}{package}

Variations on CRAN versions and release dates.

CRAN downloads{summary}/{package}

Shows number of downloads for a given package, see for details.


Several METACRAN services offer a public API. The API is over HTTP, and data is sent and received as JSON.

Package database

Database of all CRAN R packages. It is a CouchDB database, hosted at Its API is discussed at the project page:

Search service that indexes package metadata. It is provided by an Elasticsearch server, that exposes its search API. It is hosted at, and its API is the standard Elasticsearch API.

Package downloads

Download summaries from the RStudio CRAN mirror, taken from It is hosted and its API is discussed at the project page:

R versions

Small API that reports current and old R versions. It is hosted at and it API is documented at the project page:

R-builder is a script that eases building R packages from GitHub with various CI services. See its project page for details: